The 1916 Rising was the first major revolt against British rule in Ireland since the United Irishmen Rebellion of 1798.

During Easter Week 1916, the rebels succeeded in taking over large parts of Dublin city for almost a week, right under the noses of the British empire, then the largest empire in the world. For fewer than 2,000 poorly armed amateur soldiers to take on a country with the political power and military strength of Britain was astonishing.

The Rising matters because, even though the rebels surrendered, it had a huge effect. After the Rising, the British authorities executed the rebel leaders and arrested over 3,500 suspected of involvement. These moves helped convince many people to turn against the British, and seek full independence for Ireland as a separate country.

Some say the people who planned the Rising feared it was the last chance to save a sense of Irishness. At the time of the Rising, 150,000 Irishmen were fighting for Britain in the first World War.

Almost 50 years ago, Garret FitzGerald, who was taoiseach in the 1980s, and whose father had fought in the GPO in 1916, said: “It was planned by men who feared that without a dramatic gesture of this kind, the sense of national identity that had survived all the hazards of the centuries would flicker out ignominiously within their lifetime, leaving Ireland psychologically as well as legally, like Scotland, an integral part of the United Kingdom.”

The Rising has been claimed by many as the founding act of a democratic Irish state. The rebels were determined that decisions affecting Ireland would be taken in Ireland, not in the British parliament in London.

It was also the start of Ireland being seen by some other colonies as a role model for the international struggle against the British empire.

Others see the 1916 Rising as a bloody act by a few unelected individuals. The Rising, they say, increased the divisions between Ulster unionists and southern Irish nationalists, and was the start of an era of unnecessary bloodshed and violence. Many of these people say that independence for Ireland could have been achieved peacefully, without the Rising.

The Rising destroyed the Home Rule project. For 40 years, a group of Irish politicians had campaigned for an arrangement that would keep Ireland inside the British empire, but would allow some decisions be taken by Irish members of an Irish home rule parliament.

The Rising killed off this idea. After 1916, people called for recognition of the Republic that had been declared during the Rising.

The rebellion also remains important to some people because of the ideals put forward by the rebels in the Proclamation of 1916. Many of the promises made in the Proclamation – such as equality and social progress – have still not been delivered, they say.

What is indisputable is that 1916 was a hugely significant event that transformed the focus of Irish nationalism, increased divisions and made people more politically aware and active.

The 1916 Rising came to be seen as the first stage in a war of independence that resulted in the creation of the Irish Free State in 1922 and, ultimately, the formal declaration of an Irish Republic in 1949.

Diarmaid Ferriter is professor of modern history in University College Dublin